In a mixing bowl, cream the butter and sugar together until light and fluffy. Add the eggs, vanilla extract, and rum extract, mixing well.
In another bowl, combine the flour, baking powder, salt, nutmeg, and instant pudding mix. Gradually add this dry mixture to the wet ingredients, alternating with the eggnog, until well combined.
Pour the batter into a greased loaf pan.
To make the crumb topping, mix the cold butter, flour, sugar, cinnamon, and nutmeg until crumbly. Sprinkle over the batter.
Bake for 60 minutes or until a toothpick inserted in the center comes out clean.
Allow to cool before slicing.
Notes
You can add nuts or chocolate chips for extra flavor.